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Fries with your cultured beef burger?

Tissue Engineering and the science behind Schmeat

By Andrea Ochoa

 In August of 2013 the professor Mark J Post from the Department of Physiology, Maastricht University in the Netherlands gave a lot to talk about in the news. Not because he discovered the cure for VIH or how to prevent cancer, but for providing a proof of concept that one day could have huge impact on nutrition, health, environment and food.

The concept of “schmeat”, cultured beef or lab burger was born from a petri dish and basic Tissue Engineering techniques.

Tissue Engineering has been defined since 1993 by Langer and Vacanti as: “is an interdisciplinary field that applies the principles of engineering and the life sciences toward the development of biological substitutes that restore, maintain or improve tissue function” [1].

This definition was only thought probably for Regenerative Medicine purposes and there is a big debate to determine if Schmeat could be considered or not as tissue engineering.

Tissue Engineering fundamentals consist in manipulating cells to guide their behaviour through signals and scaffolds. Behaviour could be understood as growth, proliferation, differentiation or production of a specific metabolite. The most common signals used are growth factors that have specific impact on gene expression or cell metabolism. Also it not necessarily has to be in vitro or in a petri dish as many biomaterials are being developed to guide cell behaviour once implanted inside the body.

Going back to the creation of Schmeat, it was created based on muscle-specific stem cells from a cow, they were expanded and differentiated in skeletal muscle cells and fibres [2].

There is a lot of controversy about Schmeat. The first one is because right now could be very expensive to produce (£215,000). However, scalability approaches are being studied [3]. Also why would we prefer Schmeat instead of a juicy sirloin?? Well, because the world population is growing very fast and food security is a concerning issue as well the environmental consequences. Also it will bring several advantages as vegetarians could enjoy meat and bring nutritional benefits to the population, is low-fat and at long term could be sustainable. What do you think?? Would you like to try a cultured beef burger??

 If you want to know what the food experts thought about it, take a look to this video!!

https://www.youtube.com/watch?v=9XqcIkbxxBw

Signing off

Andrea, on behalf of the team

  References

1.            Langer, R. and J.P. Vacanti, TISSUE ENGINEERING. Science, 1993. 260(5110): p. 920-926.

2.            Post, M.J. and Anonymous, An alternative animal protein source: cultured beef. Frontiers in Agricultural Sustainability: Studying the Protein Supply Chain to Improve Dietary Quality, 2014. 1328: p. 29-33.

De-cellularised mouse pancreas 

Maybe have you heard about hearts synthesized outside the body that could be the perfect replacement in cases of heart disease and that this can also be done in other organs such as kidney, pancreas, among others. How is this accomplished and how far is this technology from clinical application?

Well, to start with, one common technique used to re-generate the organs is through the process of de-cellularisation. De-cellularisation, is a process where all cells are washed out from the organ to obtain the extracellular matrix or ECM and therefore keep the natural organ architecture. This ECM is a complex matrix formed by proteins and other molecules secreted by the cells themselves to generate an environment they are comfortable and stable in – like a home, this is called a cell niche.  The objective is to wash out the original cells leaving behind a scaffold with preserved ECM. The scaffold, retaining properties of the cell niche, can then be re-populated with cells which can comfortably anchor down and begin to communicate with other cells and restore tissue function.

Presently, there are some issues we need to overcome in de-cellularising tissue before clinical application. One of them is that it is hard to eliminate all cells and foreign DNA from the ECM. If these remain, the new heart will have foreign cells that are 'immunogenic' - they can be recognized by the patient’s immune system causing the implant to be reject it.

Another aspect to consider is if the de-cellularised scaffold will be implanted alone or with cells and if so, what cells to use? The most ideal condition is that the cells could be from the patient. That way, we can avoid immune-rejection as the patient's immune system will recognize cells on the scaffold seeing the implanted scaffold as 'self'. In the case of the heart, either cardiac cells or differentiated stem cells can be used. Techniques to grown and differentiate these cells further increases the complexity for translational purposes.

Even if there is still a long road to getting “a broad range of complete new organs” to the patients, there is a lot of research going to making this come true, and new enterprises have been started for the commercialization of de-cellularised scaffolds for trachea replacement, skin, nerve and vascular grafts.

You can refer to this video to learn more about de-cellularisation:

“New heart built with stem cells” (University of Minnesota) https://www.youtube.com/watch?v=j9hEFUpTVPA

Signing off

Andrea, on behalf of the team